Red starfish Dosing / Airline Tube Holder with 4 ports / holes Part # DD-04 
 
Ideal for Securing dosing and airline tubes
securely hold up to 4 tubes with set screws
Max tube / line size  8 mm
ABS material, acid and alkali resistant, corrosion resistant
Fits rim / sump or aquarium walls up to 11/16 thick 
Two set screws to secure holder in place